1. Field of the Invention:
The present invention relates, in general, to watthour meters and, specifically, to socket adapters for watthour meters.
2. Description of the Art:
Electrical power is supplied to an individual site or service by external electrical power line conductors located above or below ground. In a conventional arrangement, electrical power line conductors are connected to contacts in a watthour meter socket mounted on a building wall. Electrical load conductors are connected to another set of contacts in the socket and extend to the electrical distribution network in the building. A watthour meter is plugged into the contacts in the meter socket to measure the electric power drawn through the load conductors.
Due to the current trend toward the use of plug-in watthour meters, socket adapters have been devised which convert A-base type bottom connected watthour meter sockets to receive plug-in watthour meters. Another type of socket adapter has been devised which allows the installation of other devices between the watthour meter socket and a plug-in watthour meter. Such watthour meter socket adapters have also been provided with power disconnect devices, such as circuit breakers or ground fault circuit interrupters, both for protecting the electrical service as well as, in certain applications, to limit the amount of power supplied to the site. Such power disconnect devices may include an elongated plunger, the end of which extends outwardly through an opening in the annular side wall of the socket adapter when the circuit breaker is in the open or power disconnected position. The exposed end of the plunger can be pushed through the side wall of the watthour meter socket adapter to close the circuit breaker and to reapply power to the site. In certain of these devices, the ends of the plungers extending through the sidewall of the adapter have been colored red for high visibility of a tripped or open condition of the circuit breaker, etc.
For special applications, auxiliary enclosures or boxes have been attached to or mounted on the watthour meter socket and/or socket adapter. Such enclosures or boxes contain an electrical outlet or other electrical connector attached to the power line or load contacts in the watthour meter socket or socket adapter for powering external devices mounted in the auxiliary enclosure. Examples of such auxiliary enclosures include a temporary metered power adapter, Model numbers TMP SP2600 and TMP 2649, and the watthour meter socket adapter with interface connection disclosed in U.S. Pat. No. 4,977,482, both sold and/or owned by Ekstrom Industries, Inc., Farmington Hills, Mich., the assignee of the present invention, as well as the temporary metered power devices disclosed in U.S. Pat. Nos. 5,097,383 and 5,216,802. When such auxiliary outlets or connectors are used, the power supplied to the outlet or connector may be either metered or unmetered.
It is also known to construct a watthour meter socket adapter as a temporary service adapter, such as a temporary service adapter, model 700 series sold by Ekstrom Industries, Inc. In such an adapter, lugs are connected to the line contacts in the socket adapter and provide a connection for a cable which passes through the side wall of the socket adapter to a second, remotely spaced socket adapter to provide electrical power to a remote site from a primary site.
It is also known to construct watthour meter socket adapters which contain two side-by-side watthour meter receiving shells as shown by the 5000 series 2 in trough in-series adapters sold by Ekstrom Industries, Inc. In such a dual watthour meter socket adapter, a single base is provided with blade terminals which plug into the jaw contacts in a single watthour meter socket. The blade extensions of jaw contacts in each shell of the adapter are connected by electrical conductors to the blade terminals in the base. In such a dual watthour meter socket adapter, the load contacts of one shell are connected to the line contacts in the adjacent shell and the load contacts in the adjacent shell are connected to the load distribution network of a building or house. This dual adapter disposes two watthour meters plugged into the respective shells in series with each other for comparative testing of two meters, load surveys, metering of both reactive power and kilowatt hours, etc.
Such devices are not suitable for applications where an auxiliary electrical service separate from the primary metered service supplied to a site is needed for example, a separate metered service to an outlet supplying power to recharge an electric vehicle. Thus, it would be desirable to provide a separate metered electrical service at a single meter socket which is accessible separate from the primary metered service. It would also be desirable to provide a dual watthour meter socket adapter which includes an auxiliary enclosure containing electrical connections connected to the load contacts of one of the watthour meter sockets to enable external conductors or cables to be easily connected to the second metered service without interrupting the primary metered service through the other watthour meter in the socket adapter. It would also be desirable to provide a dual watthour meter socket adapter which includes a power disconnect device having an extendible rod accessible exteriorly of the watthour meter socket adapter to close the power disconnect device as well as to provide an easily visible indication that the power disconnect device is in the open or off position. It would also be desirable to provide a dual watthour meter socket adapter in which the external portion of the rod may be locked in the extended position to provide safe access to the conductors in an auxiliary enclosure attached to the watthour meter socket adapter.